I don’t feel like I’m doing enough for my autistic toddler

I know the feeling of having a problem and being impelled to throw everything at it, including the kitchen sink. However, things often can work out through gradual improvements. My daughter had a very restricted diet when she was very young, at one stage just cheese sandwiches and one type of baby food in a jar, but we kept negotiating with her to try new things most mealtimes. By the time she was about 6 years old her diet had expanded hugely and within another couple of years her diet was entirely normal. 

Sorry, just to add:

This might also be helpful, as you need emotional support yourself, too - preferably from people who understand what you're dealing with and going through:

NAS - Parent to Parent Emotional Support Helpline

He’s recently started attending a specialised nursery setting and I’ve been speaking with other mums and I feel that they know more/do more/ have more people involved. Before attending I thought I was doing everything available but it seems not. I don’t want him to be at a disadvantage if there is more support out there for him. But yes, your right, I probably do need to relax a bit

If you are in or near Cambridgeshire or Peterborough then I recommend you try to attend some of their Zoom meetings especially their Tii Hub. Excellent source of info and support from others who have been through what you ard going tthrough. Google "Pinpoint Cambridgeshire" 

Hi and welcome to the community!

You might find these resources helpful:

NICE - Autism spectrum disorder in under 19s: support and management

NAS - Formal support following an autism diagnosis

Kids SENDIASS

You seem to be very effectively organising support for your son. Perhaps just enjoying having your son and relaxing a little with him would be beneficial for both of you?

I am myself autistic and have an autistic daughter, now 23 years old.